By compared to the vacuum plasma technology, the atmospheric pressure plasma operated under an atmosphere environment can work without an expensive vacuum chamber and the complicated vacuuming equipments, and thus the equipment investment thereupon can be greatly reduced. In addition, the atmospheric pressure plasma also has various advantages in no limitation upon the chamber size, being easily extendable, being highly applicable to the in-line process and so on. In particular, the atmospheric pressure plasma can be applied to various surface treatment of a base plate, such as cleaning, activating, etching, etc. Besides, the atmospheric pressure plasma can be also relevant to the coating by deposition for the base plates.
In the art, the mega linear plasma processing apparatus specifically for processing large-size base plates is featured in rapid processing for many applications such as surface cleaning, activating, reducing, coating and so on. In the market, facilities for processing the linear plasma are already provided by major manufacturers. Nevertheless, for manufacturing of the modularized linear-plasma apparatus needs a substantial amount of heat-resistant insulating material, and further for the large-size heat-resistant insulating material such as the 1-m PEEK, Teflon or Ceramics, is hard to obtain in the free market, the combined cost of the mega apparatus is high and kind of long way to be reduced. Further, in order to handle different sizes of mega base plates, it is infeasible to prepare many facilities with different capacities and varied structuring. In addition, the engineering of manufacturing a mega plasma facility is complicated in various practical manifolds. For example, in a plasma manufacturing process, the in-process temperature is significant to affect the deformation of the electrode. Therefore, a large amount of cooling water is usually supplied to the electrode so as to stabilize the temperature of the electrode. However, in practice, difficulty of constructing the channel for conveying the cooling water is raised as the increase of the length of the electrode.
In a patented technology, a plurality of parallel plasma source is arranged in a linear manner, and the corresponding electrodes are parallel connected, such that individual plasma sources can produce a series of parallel plasmas by introducing respective process gases. While in handling a mega base plate, the number of the electrode sources can be extended to meet the size requirement. However, such a construction of the modularized linear plasma apparatus would face a problem of uneven distribution of the plasma, and thus can only be applied to the manufacturing of the direct-type plasma.
In another disclosure, a plurality of parallel insulating pipes is arranged between two electrodes in a predetermined linear, circular or rectangular pattern. A series of plasmas are produced by introducing process gas into each of the insulating pipes. Through the serial connection of the insulating pipes, a patterned and mega application of plasma can be achieved. However, in such a technique, as long as the configuration and the size of the electrode is determined, the extension of the whole apparatus is no more possible. In addition, the resulted uneven distribution of the plasma can only be applied to the direct-type plasma.